Enclosed arc device



Dec. 12, 1933. F. WEINBERG ENCLOSED ARC DEVICE Filed June '7, 192

I N V EN TOR. Ease/ck h/wgm A TTORNE Y.

Patented Dec. 12, 1933 UNITED STATES PATENT OFFICE 10 Claims.

My invention relates to an improved electric light. It pertains particularly to improvements in electric arc lights wherein the arc is located within a sealed container.

The object is to provide an improved arc light of this character which possesses unusually high efiiciency and long life and which is completely self-contained in that it will almost instantly respond upon the closing of the control switch in the current supply circuit and without the aid of auxiliary starting devices of any kind.

My improved light is so constructed that it may be disposed at any angle. It is adaptable for use within the ordinary light sockets. It operates upon light current of conventional voltage and it responds to the same current for starting.

Other important and material objects and advantages will more fully appear from the following description, appended claims and accompanying drawing which illustrates one embodiment of my invention and in which:

Figure 1 is a vertical sectional view through my improved electric are light.

. Fig. 2 is a vertical sectional view taken at right angles to the view in Fig. 1.

Fig. 3 is a horizontal sectional view taken on line 3-3, Fig. 1.

The container or glass bulb is indicated as 10. This bulb carries a threaded end 12 adapted to be received within the conventional light socket. The bulb has been exhausted of air and filled with a suitable inert gas, such as argon neon helium or a mixture of these gases. It is provided with contacts 14 and 16. A pair of spacedapart electrodes 18 and 20 formed of a suitable refractory material are mounted within the bulb. Electrode 18 leads into the bulb from contact 14 and terminates in a ball end 22. Electrode 20 leads into the bulb from contact 16 and terminates in a ball end 24. These ball ends are disposed in opposed relationship and spaced apart to form a gap 25, which gap may vary in magnitude but is relatively small. The ball ends of the electially high melting point, such as tungsten or trodes are formed of a material having a substanthe aforementioned point of comparative proximity.

This point of closest approach of the two electrodes is surrounded by an enclosure or cage 26 spaced from the electrodes. This cage may be 68 supported either by the electrodes themselves or by the container, as shown in the drawing.

The cage is formed of suitable heat, light and electric insulating material. Within the cage and within the field of the electrodes I place suitable material of the alkali metal group such as potassium or sodium. This material is of such a character as to facilitate ionization of the gas space within the cage and particularly in the interval between the electrodes. This alkali metal mat- 70 ter is deposited on the wall of the cage or amalgamated as with tin or mercury to form plates 28 and 30. Plate 28 is connected with electrode 18 and plate 30 is connected with electrode 20. These plates 28 and 30 are insulated from each other.

After leaving the cage the electrodes are bent in such a manner that the arcing gap 25 is out of line with the interior of the cage 26. One reason for thuspositioning this arcing gap is to avoid the deleterious photoelectric effect the arc would have on the alkali metal disposed within the cage. Otherwise the arc would so affect the alkali metal as to encourage loss of electrons and the deteriorating, tiring effect of the metal would materially reduce its capacity to initiate the formatlonof the arc. Therefore,

I protect the alkali metal within the shadow of the cage. The presence of the cage prevents the diffusion of the alkali electrons thereby adding greatly to the eflicient bombardment of the gas atoms within.

The action of my light is as follows: The bulb being inserted in an ordinary light socket and the control switch turned on, a current of the usual character of approximately 110 volts potential, which may be either alternating or direct current, enters the electrodes. The extent of the gap 25 is too great to permit ionization of the gas space between the ball ends of the electrodes which would encourage arcing at such point but within the cage the fleld formed by the current in the electrodes pulls the loosely bound valence electrons out of the alkali metal and they bombard the electrons of the inert gas atoms, 1 thereby dislodging them to the ionization level of the atom and producing a state of ionization of the gas between the electrodes which results in the formation of an electric discharge at this point.

Due to the direction of the magnetic field surrounding the electrodes this electric discharge is driven outwardly along the electrodes until it reaches the gap 25. It bridges this gap and forms an arc at such point. The magnetic fleld at the gap is not antagonistic to the maintenance of a stable arc because of the .opposed relationship of the balls and because of the ofiset position of the gap with reference to the electrodes, and the arc, therefore, remains constant at this point until the current is turned ofl.

This gap is preferably positioned in the center of the bulb so that as little heat as possible is lost to the wall of the bulb and also in order that the evaporation of the atoms at the ends of the electrodes is as far removed as possible from the wall of the bulb, thereby minimiz ing the deposit of blackening matter on said wall.

Upon the establishment of the arc at the gap 25 there is a drop in voltage at the electrodes whichdecreases the strength of the electric field between the plates and as a result few, if any, electrons are pulled out of the alkali metal, thereby inhibiting the formation of an arc inside the cage during the persistence of the are at the gap 25.

The electrodes should possess sufflcient resistance to choke the current and I accomplish this by providing ball ends formed of tungsten, cerium, suitable oxides or other similar materials which possess high electric as well as heat resisting capacity. Otherwise some artificial resistance should be shunted into the circuit at a convenient point and preferably where it might serve a number of lights.

What I claim'is:

1. The combination in an electric light, of spaced-apart co-operating electrodes mounted within a sealed container separated at their tips by a gap of greater magnitude than at a point remote therefrom and having material of the alkali metal group associated therewith at such remote point of less magnitude responsive to a light current of conventional voltage to induce a discharge at such point which is driven outwardly by the magnetic influence of the current through the electrodes and established at the tips thereof.

2. The combination in an electric light, of spaced-apart co-operating electrodes mounted within a sealed container separated at their tips by a gap of greater magnitude thanat a point remote therefrom and having material of the alkali metal group connected with one of said electrodes at such remote point of less magnitude whereby a discharge is established at such point responsive to the magnetic influence of the current through the electrodes to travel outwardly to their tips.

' 3. The combination in an electric light, of

spaced-apart co-operating electrodes mounted.

within a sealed container separated at their tips by a gap of greater magnitude than at a point remote therefrom and having associated therewith at such remote point of less magnitude "a deposit of alkali metal connected with each electrode, said deposits being insulated from each other and adapted to produce ionization of the gas between the electrodes to establish a discharge at such point responsive to the current through the electrodes to be driven outwardly to the tips.

4. The combination in an electric light, of

spaced-apart co-operating electrodes mounted within a sealed container and vhaving tip portions separated by a gap of greater magnitude than the distance which separates the electrodes at a determined point remote from their tips, a cage about said electrodes at such remote point of less magnitude, and an alkali metal deposit carried by said cage to facilitate initial discharging between the electrodes at such point responsive to the current through the electrodes to be driven outwardly to their tips.

5. An electric are light, comprising a sealed container filled with an inert gas, electrodes mounted therein having current connections and provided with opposed tips separated by a gap for arcing, said gap being of greater magnitude than the distance between said electrodes at a point remote from the gap, a cage of insulating material about said electrodes at such remote point of less magnitude, and material of the alkali metal group separated into two insulated patches one connected with one electrode and the other connected with the other electrode responsive to the conventional light current to establish temporarily a discharge at such point subject to the current through the electrodes to travel outwardly thereover to their tips.

6. an electric arc light provided with electrodes separated at their tips by a gap for arcing and characterized by the provision of a cage about the electrodes at a point remote from their tips, and material within said cage responsive to the conventional low voltage light current to facilitate initial arcing between the electrodes within the cage, the are being responsive to the current through the electrodes to travel outwardly 1 0 to their tips.

'l. The combination in an electric light, of spaced apart cooperating electrodes mounted within a sealed gas-filled container, said electrodes provided with current connections and 5 separated at their tips, a material disposed in proximity to the electrodes at a point remote from their tips responsive to the conventional light current to facilitate ionization of the gas between the electrodes to establish a discharge 12 at such point responsive to the current through the electrodes to be driven outwardly to their tips, and means to protect said material from the influence of the actinic arc rays.

8. An electric are light provided with spaced 125 apart electrodes separated at their tips by a gap for arcing and provided with a cage about the electrodes at a point remote from their tips, material within the cage adapted to facilitate ionization of gas between the electrodes and responsive to the normal low voltage light current to establish temporarily an electric discharge at such point responsive to the current through the electrodes to travel outwardly to produce a permanent are at their tips, said tips extending beyond said cage and being offset with respect to their point of outlet from the cage.

9. An electric are light including a gas filled container enclosing a material to initiate an electric discharge, electrodes in said container and means to shield said material from the rays of the discharge to avoid deterioration.

10. An electric arc light provided with'electrodes separated at their tips by a gap for arcing and characterized by the provision of a cage about the electrodes at'their lower ends only and material within said cage to facilitate a discharge between the electrodes.

FREDERICK WEINBERG.

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